Adsorption of ethyl, iso-propyl, n-butyl and iso-butyl mercaptans on AgX zeolite: Equilibrium and kinetic study

It has been shown that AgX zeolite has a distinctly higher adsorption capacity compared to NaX, NiX and NiAgX zeolites for ethyl mercaptan. Chosen as the best adsorbent, the adsorption isotherms of ethyl, iso-propyl, n-butyl and iso butyl mercaptans on AgX zeolite at three different temperatures of 26, 40 and 60 °C had been studied. The AgX zeolite showed the highest adsorption capacity for the ethyl mercaptan adsorbate molecule. On the other hand, this mercaptan molecule was the easiest to be removed by thermal treatment in the range of 150–300 °C. Except ethyl mercaptan, all the other mercaptan molecules showed increased adsorption on AgX zeolite with increasing the temperature in the range of 26–60 °C. The kinetic analysis of the adsorption process showed that there exists a rational correlation between the size and configuration (linear or branched) of the molecules and the effective diffusion coefficient.